Information is shared across distributed systems, or networks, generally by either a messaging scheme or a shared virtual memory mechanism. The messaging schemes typically require that the system nodes maintain up-to-date topology information. Further, the nodes must exchange certain specific series of messages to convey desired information between the nodes, and may require that the nodes send queries to determine, for example, if any changes in status have occurred. The messaging schemes are thus relatively difficult to use for certain applications. Also, if one or more of the nodes fail, the messaging schemes may become unreliable.
The shared memory systems do not scale well, since they require the nodes to coordinate their shared memory activities across the network. Accordingly, the complexity of these systems increases as the number of nodes increases.
The invention is a replicated management information base (RMIB), or replicated spreadsheet, that includes columns, or categories, of information to be shared and rows for the respective xe2x80x9cmemberxe2x80x9d nodes, and also a system for maintaining the RMIB. Each member node maintains a copy, or view, of the RMIB, and is responsible for the contents of its own row. When the node updates its row, the node sends out an update message to the other members. As the update message propagates through the membership, each member updates the row in its copy of the RMIB. The node-specific information in the RMIB is readily updated without requiring the nodes to, for example, inquire about the status of other nodes or coordinate shared memory activities, as is required by known prior systems.
For more robust implementation, the nodes include version numbers in the update messages, so that the receiving node ignores older messages or at least applies the messages in order, as discussed below. Further, the member nodes may gossip among themselves, to ensure that each node receives the most recent updates, also as discussed below.